Steam trap



v a 3 g 4 v F m 0 1 l I l l I II a i ii- I a 0 a w 7 AW, Z I F 7 b l July 28', 1931. G. F. M D OUGALL STEAI TRAP 7 Filed Aug. 4. 1930 Inventor GEORGE E MDOUGALL.

Attorney Patented July 28, 1931 GEORGE F. MCDOUGALL, oEroR TLAND,- onneon 5 ma n TRAP Applicationfiled August 4, 1930..

My invention is related to'that class of appliances, the purpose of which is to relieve heating systems, pipe lines and such like containing steam under pressure from the water that results from condensation of the steam and instead of being controlled by a float device, its operation is regulated and controlled by temperature changes in the substance to be discharged.

The following drawings accompany and form apart of this specification and illustrate by graphic. representation the various figures referred to in the text.

Fig. I is a longitudinal sectional elevation of my new trap showing the interiorarrangement of construction; and

a Fig. II is an end View of the right'hand end of Fig. I. i The trap body, 1, is inf'the form ofja hollow shell shown here to be substantiallya cylinder having a length somewhat greater thanthe diameter, though wide variations in this construction are possible. r

Interiorlyof the shell there aretwo chambers, the high pressure chamber, 2, which willbe drectly connected to the system o'fpipf ing or the like to be drained, the connection being made at the inlet, 2a, and a low pressure. chamber, 3, occupying an adjacent portion of the interior of the shell. A partition, 4, the difierent portions of which are designated 4a and 1b, constitute a complete closure between the. two chambers, 2 and 3, except for a valve opening, 5, which .is controlled by a voluntary type valve,.6, which in turn is influenced by the thermostatic bar, 7', construction details of which are hereinafter given. 1

An outlet for the low pressure chamber,

3, is provided by' the slphon-pipe, 8, which communicates with the outlet opening, 106, by means of the disc, 10. a

The disc, 10, will have an opening, 10a, the cross-sectional area of which is always less than the cross-sectional area of the valve opening, 5.

The thermostaticbar, Z, is made up of two metals having different degrees of ex pansibility under the influence of temperature changes.

' forms of construction For example, such as brass and.

serial No. 472,918. A g

And many different other than thatshown will be available to util'izethe principle.- In

untempered steel.

. this case, 7 a will be considered to be brass and The axis of the ther-y shown tobe a straight I will be understood that" it 76', untempered steel. mostatic bar, 7 0, is here line, though it will be straight only at one temperature and that any cooling off of the bar below that 4 fixed temperature will tend to cause the bar to deflect upward toward the line Ydand any increase in temperature will cause the line to deflect downward toward the line "7 ,"i*'or the reasonthat the upper half, 7 aof the thrmostatic bar, 7, expandsandcontrac-t's very much more than the lower half, 71). This deflection of the thermostatic bar member produces a movement appr-oxim'atelyatright angles to the axis of the thermostaticfbar that is very much greater than the actual lineal expansion of that part designated 7 a, and consequently gives ita greaterrange of movement for valve controlthanitl could possibly have were it arranged to. simply utis v 75 80, is shown attached by the fastening, 9, to

lize the lineal expansion of the metal; A cage,

the end of the 'thermostaticbar, 7 to act as a retainer for the valve .member, '6, andthe thermostatic bar, 17 is. shown tobe pivoted on the pin, 12, and tofbeadjustable toward and away from the valve by manipulation of the set-screws 13' and leg-these being shown as a. diagrammatic means for securing the desired adjustment While 1 still holding the thermostatic bar ,7 rigid in a select position. A gage glass, 15,'having gage cocks,- 1 6;and

17, will be in communication with the law pressure chamber, 3, to show the contained water level when a trap to assist in securing the proper adjustment ofthe setscrews13 and is providedto relieve the low pressure chamber, v V placed'in service and a plug, 19, is provided be placed in position, plugs 20 and 21 being for the purpose ofremoving scale andsedi ment on occasion, I

In operationj thetra p will be. connected 1'60 1 a systemthatit is de ed to a nfirid fli is in operation and; i 99; 14. Anair 9001?,118, the air from the to ibf 3, when th'e trap is i so t th n r p r y h devicemay .95". I

: stricted by the mechanism of the trap so long line 76 and-effect a of less discharge opem e' 5 1S as the condensate is substantially cold. As soon as the temperature within the low pressure chamber, 8, rises to a point determined by the adjustment of the thermostatic bar, 7 heat will tend to deflect the end of the bar toward the point designated by-the dotted closure of the valve, 6, on tending to restrict or the valve opening, 5,

As soon as this takes interrupt the how.

vplace any accumulated pressure in the low pressure chamber, 3, will be relieved through the opening, "10a, of the. disc 10; the water level will tend to drop, the pressure will drop with it and: pressure andtemperature being functions ofeach other-in steam, the temperature will drop atthe same tune.

The purpose of making the opening, 10a, capacity than the valve so that the pressure and consequent temperature in the low pressure chamber,.3, can rise above atmosphere and produce a corresponding temperature in ,the thermostatic bar, 7 ,to promote quick action upon the valve, 6. i a I it will'be found in operation that the low pressure chamber, 3, will always contain water vapor at greater or less temperature and that the waterline of the V that'the valve,

tending sired rangeof operation.

we I spirit of this to a low pressure chamber should be adjusted by manipulation ofthe setscrews', l3 and lt, so that it is'just below the bottom of the thermostatic bar, 7.

. In manufacturing the thermostatic bar, 7

I the joint, 70, will ordinarily be brazed or hard soldered but it will be found expedient to also put in a fastening, 9b, owing tendency that the difference in enpansibility has to disrupt a brazed joint. v

If this trap is properly constructed accord-' ing to the disclosure heretofore given it will be found to'be athe mostatic trap having an of capacity and great sensitiveness and is believed to'be in this resuperior to thetype of thermostatic trap using expansible fluids to secui'ethe de- It has another very desirable feature in 6, tends to act as, a check valve and will; prevent cross traps are connected to'several systems using steam and to a common discharge conduit.-

QAYvery'wide variation in construction details. maybe had without departing from the invention." For example, thermostatic bar, even approximately so, and it may be curved like a shepherds crook with the end thereof to influence the valve, and it will be understood that this disclosure merely shows an operative'wayof building the trap and to the flow where several I what is deemed to be new and desired to secure by Letters Patent, is-

1. In a steam trap, a receiving compartment and a discharge compartment and a voluntary valve between the two said partments, and a thermostatic bar control for said valve, said valve being located in the discharge compartment, in combination with a discharge outlet for said discharge compartment having less capacity than said valve. v V

2. Ina steam trap, ment and a discharge compartment and a valve between thetwo said compartments located in said discharge compartment, and a thermostatic bar control for the said valve COIII- I a receiving compart- Q built of diverse metals forthe purpose lndiand a restricted outlet for said siphon pipe for the vpurpose specified, 1

4:. Inja steam trap, a. receiving compartment and a discharge compartment and a check :valve between the two said compartments and a thermostatic bar element tending to close the said check valve under the influence of temperature increase, thesaid thermost'atlc elementutil zmg the different 10 expanslbility of diverse f metals to'defiect a closure contact to influence the valve, in combinationwvith a siphon pipe having a restricted bushing; outlet for the purpose specified. I r

' 5. In a steam trap, a receivmg compartment, a discharge compartment and a onethe two -sa1d compart way valve between ments and a thermostatic bar element of the character describedtoeffect control ofsaidl valve, and means fo ';adjustii1g the said thermostatic-bar element in coi'bination with a siphon pipe having an inserted restricted outlet bushing member.

cnonen eDoUeALL.

I the t, '7, need not be straight or 

